DE102021119484A1 - Cell holder for holding battery cells and cell module - Google Patents

Abstract

Cell holder (1) for holding cylindrical battery cells (2), preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell holder (1) having: a plurality of holding sections (10), each having a base (11) and Have side walls (12) and thus each form a section which is set up to accommodate and fix a base surface (2a) and at least sections of a lateral surface (2b) of each battery cell (2); wherein the side walls (12) of the respective holding sections (10) comprise: at least one contact surface (12a), which is arranged in a contact area to the battery cell (2) essentially perpendicularly to the base (11) and is set up to, when the battery cell (2) is inserted to be in planar or linear contact with a section of a lateral surface (2b) of the battery cell (2), and at least one deformable contact section (12b), which is set up to move when the battery cell (2) is inserted into the corresponding holding section (10 ) to deform.

Description

technical field

The present invention relates to a cell holder for holding at least one cylindrical battery cell, preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, and a method for producing a cell holder.

State of the art

Battery systems for electric and hybrid vehicles as well as vehicles with fuel cells are the subject of current research and development. Typically, several cylindrical battery cells are combined into a battery module, also known as a "battery pack". A traction battery for a vehicle in turn comprises one or more battery modules.

A battery module has cell holders whose task is to mechanically fix the battery cells and thus combine them into a larger unit, the battery module. The cell holders can be constructed in one piece or in multiple pieces from molded parts, or they can be made entirely or partially from potting compound after the initial placement of the battery cells for their permanent fixation in the battery housing.

A well-known design uses honeycomb cell holder, such as in U.S. 2010/0136413 A1 described. In this case, the battery cells are arranged parallel to one another, standing upright and staggered in rows, so that they form a structure of the densest circular packing, viewed in cross section to the longitudinal extent of the battery cells. The battery cells are held on both sides in the axial direction by a cell holder each, which has cup-shaped depressions corresponding to the battery cells, into which the battery cells are inserted.

the 1 shows a section of an exemplary cell holder 1 with cup-shaped holding sections 10 in cross section, which are formed by a bottom 11 and side walls 12 . The holding sections 10 are set up in such a way that they receive an axial end of each battery cell 2 and fix it in the directions parallel to the floor 11 and directed towards the floor 11 . The battery cell 2 is upright when installed, ie its axial direction or cell axis A is perpendicular to the floor 11. By using two such cell holders 1, each of which fixes one end of the battery cells 2, the battery cells 2 are held in a sandwich-like manner and thus form a cell module or battery module.

It is known to produce the cell holder 1 as an injection molded plastic part. However, such injection-molded cell holders have so-called draft angles or draft angles in order to be able to be easily demoulded from their mold. For illustration, the draft angles α, which are manifested by a narrowing of the side walls 12 starting from the base 11 in the axial direction, are in FIG 1 drawn exaggerated. After the plastic has hardened, the cell holder 1 is removed from the mold (not shown in the figures) along a demolding direction E, which runs parallel to the cell axis A.

Such production-related draft angles stand in the way of a defined and planar contact of the side walls with the battery cells. The battery cells tend to be supported by the side walls only along a line contour, cf. contact areas K in FIG 1 , but not flat, which makes exact positioning and alignment, as well as a secure hold of the battery cells, more difficult. This also has a disadvantageous effect on the assembly, which may have to be carried out with a not inconsiderable clearance fit. The interface between battery cells and cell holder is also sensitive to manufacturing tolerances of the cell holder and the battery cells. A holding section, the side walls of which run completely around the corresponding battery cell, generally results in an increased installation space, but in particular also due to the thickening on the bottom side due to the draft angle.

When arranging the battery cells, care must be taken to ensure that a sufficient distance is maintained between adjacent battery cells in order to prevent thermal propagation to adjacent cells in the event of a so-called "thermal runaway" of a battery cell and to rule out a short circuit. To this end, it is common to design the cell holders to ensure adequate spacing between the battery cells. In this case, the battery cells form a cell pattern, for example square or hexagonal, in which neighboring cells all have the same distance from one another.

However, the probability of a short circuit between adjacent battery cells depends not only on the distance but also on how they are connected. Thus, a greater distance must be maintained between adjacent battery cells that are electrically connected in series with one another than between adjacent battery cells that are electrically connected in parallel. As a rule, however, today's cell holders have identical cell distances, which for safety reasons then meet the requirements for the distance between two cells connected in series Battery cells must suffice. If the electrical wiring within a battery module is known and cannot be changed, this results in a suboptimal packing density of the battery cells and thus a suboptimal energy density. If the cell holder is to enable different electrical wiring patterns, the number of technically sensible configurations is nevertheless limited, so that in these cases most cell spacings are kept unnecessarily large. In addition to the loss of energy density, larger cell distances also result in more material being used in the cell holder and in higher weight.

Presentation of the invention

An object of the invention is to provide an improved cell holder for holding at least one cylindrical battery cell and an improved cell module.

The object is achieved by a cell holder having the features of claim 1, a cell holder having the features of claim 8 and a cell module having the features of claim 13. Advantageous developments follow from the dependent claims, the following description of the invention and the description of preferred exemplary embodiments.

The cell holder set forth herein is preferably for use in a traction battery for electric, hybrid or fuel cell vehicles. A cell module or battery module, usually with a plurality of battery cells, can have one or two cell holders in order to combine and hold or fix the battery cells.

The cell holder according to the invention comprises a plurality of holding sections, each of which has a base and side walls and thus forms a (preferably concave) section which is set up to accommodate an axial end of each battery cell, i.e. a base area and at least sections of the outer surface of the battery cell and to fix. The cylindrical shape of the battery cell defines a cell axis and a lateral surface that extends along the cell axis and in the circumferential direction of the battery cell. The battery cell is fixed by the cell holder in at least one direction, but preferably in several directions. The base and the side walls are preferably set up in such a way that they fix the corresponding battery cell in all directions parallel to the base and in the direction of the base.

The side walls of the respective holding sections comprise at least one contact surface, which is arranged in a contact area to the battery cell essentially perpendicular to the floor and is set up to be in planar or linear contact with a section of a lateral surface of the battery cell when the battery cell is inserted, and at least one deformable one Contact section that is set up to deform when the battery cell is inserted into the corresponding holding section. The contact surface is preferably not deformed in this case.

In other words, the concavely curved contact surface matches a corresponding section of the lateral surface of the battery cell, so that there is a planar contact. The deformable contact section is located elsewhere, preferably opposite the contact surface. The contact portion is preferably elastically deformable so that it acts like a spring.

The contact surface preferably has a cylindrical or part-cylindrical shape. It should be noted that the terms "cylindrical" and "circular" do not have to define a complete cylinder circumference or circle, but that the contour of a corresponding segment is included, since the contact surface does not completely surround the battery cell, but only on a partial section of the battery cell circumference , for example in the range from 20° to 90°, rests flat.

The cell holder constructed in this way can be produced in a resource- and cost-efficient manner, since the geometries of the holding sections with the corresponding side walls can be produced in a simple manner, for example by injection molding. The holding sections enable exact positioning and alignment as well as a defined mechanical connection of the battery cell(s) to the cell holder. Cell assembly is facilitated by the deformable contact section. The holding sections also allow the battery cells to be arranged directly next to one another in a particularly space-saving manner, since the lateral surface of an inserted battery cell can remain free between the contact areas and does not have to be completely surrounded by the material of the cell holder. The effects achieved are also comparatively insensitive to manufacturing tolerances of the cell holder and the battery cells. Due to the insensitivity to fluctuating cell diameters, the cell holder is able to hold battery cells from different manufacturers without modification, which means that resources and costs can be saved if battery cell types/manufacturers are changed.

Preferably, the contact surface is connected to the ground, whereby that area of the corresponding holding section which is decisive for the Position and orientation of the battery cell defined, is particularly stable. The bottom and the contact surface are preferably formed in one piece.

The deformable contact section is preferably not connected to the floor, which means that the deformability can be implemented in a structurally simple manner.

The contact surface is preferably curved in a concave manner, in particular in a circular manner, in a cross section parallel to the base, as a result of which it interacts optimally with a correspondingly shaped circular-cylindrical battery cell.

Preferably, without a battery cell inserted, the contact surface and the deformable contact portion form a non-zero angle as viewed in a cross-section perpendicular to the ground. In this way, tolerances can be compensated and the fixation of the battery cell can be improved. Furthermore, the deformable contact section thus functions as an insertion chamfer for a corresponding battery cell.

The holding sections preferably each comprise a plurality of, in particular precisely two, deformable contact sections, as a result of which the fixing and correct alignment of the corresponding battery cell are improved and the holder is stabilized. The features, technical effects and advantages that have been described in relation to the use of a deformable contact section apply analogously to any further deformable contact sections.

Preferably, the side wall of a holding section that carries the contact surface has a deformable contact section of an adjacent holding section. In other words, the contact surface and the one or more deformable contact sections of an adjacent holding section are preferably formed in one piece and by exactly one structural part. In this way, adjacent holding sections are structurally integrated with one another, as a result of which the cell holder can be made particularly compact.

The cell holder is preferably made of plastic, in particular in an injection molding process. The cell holder is preferably designed in one piece. The cell holder according to one of the embodiment variants presented above is particularly suitable as an injection molded part, since its structural nature and the manufacturing process interact synergistically, as becomes clear from the description of the process.

The above object is further achieved by a cell holder for holding cylindrical battery cells, preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell holder having: a plurality of holding sections, each having a bottom and side walls and so each form a section which is set up to accommodate and fix a base area and at least in sections a lateral surface of each battery cell; wherein the holding sections are set up in such a way that battery cells inserted therein have at least partially different distances to their nearest neighbors.

The cell holder may have one or more of the features defined above. The technical effects, advantages and exemplary embodiments described then apply analogously to the cell holder defined above.

When measuring the distance, the shortest distance between the lateral surfaces of the corresponding, adjacent battery cells in a sectional plane perpendicular to the cell axes is used. Furthermore, it should be pointed out that the holding sections clearly specify the position and orientation of the battery cells, so that the battery cells in the inserted state, in particular their spacings defined above, imply a structural definition of the holding sections. A fully populated cell holder is assumed to determine the distance between adjacent battery cells, so that different distances due to unoccupied holding sections are ruled out.

By constructing the cell holder in such a way that its holding sections allow different distances between the battery cells used, the packing density of the battery cells can be optimized in comparison to equidistant cell placement without sacrificing safety. This results in less material being used, lower costs and a lower weight of the cell holder.

A plurality of holding sections, for example three, are preferably combined to form a cell group each, as a result of which the advantage of a high packing density is combined with maintaining flexibility with regard to the electrical wiring.

Adjacent cell groups are preferably separated from one another by means of a group wall, which increases the electrical insulation and/or mechanical safety. The cell groups are thus preferably separated from one another by stabilizing webs or group walls. There are no such group walls within the cell groups. Depending on the application, material of the Cell holder, requirement for stability and the like, more or fewer holding sections can be combined into a cell group. Such a combination in turn results in material and space savings, as a result of which the cell modules made up of the battery cells and one or two of the cell holders shown here can be of particularly compact design.

The holding sections are preferably set up in such a way that the distance between adjacent battery cells within a cell group is smaller than the distance between adjacent battery cells in adjacent cell groups.

From a purely electrical point of view, in extreme cases, a cell module can include an entire battery group (=logical cell, group of battery cells connected in parallel) in order to achieve maximum packing density. For mechanical reasons, however, such a battery group is preferably divided into a number of cell groups with corresponding cell walls, which also allows flexibility with regard to possible electrical interconnections without having to change the structure or the design of the cell holder for this purpose. Compared to a conventional design, a higher packing density is still achieved with less material used, while maintaining flexibility in terms of electrical wiring and safety.

The holding sections are preferably arranged in rows, with the holding sections of adjacent rows particularly preferably being arranged offset, approximately offset by the dimension of half a holding section. In this way, a honeycomb structure or a structure of the closest circular packing can be produced, viewed in a cross section parallel to the ground. In this way, the number of battery cells accommodated per unit area can be maximized.

For the same reason, one or more of the holding sections are preferably designed in such a way that their side walls do not completely enclose the lateral surface of a corresponding battery cell that is used. The grouping of the holding sections described above can thereby be created or at least supported.

The holding sections of each cell group are preferably in a row, i.e. in this case the cell groups do not span several rows, which means that a good compromise between flexibility of the electrical wiring and mechanical stability is achieved.

The above object is also achieved by a cell module, preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell module having: at least one cell holder according to one of the embodiment variants described above; a plurality of battery cells each inserted into a holding portion of the cell holder and fixed thereby; and a wiring portion that electrically connects the battery cells to each other. The cell module preferably has two cell holders which sandwich the battery cells.

The features, technical effects, advantages and exemplary embodiments that have been described in relation to the cell holder apply analogously to the cell module equipped with them.

The connection section is preferably set up in such a way that battery cells within a cell group are connected in parallel, while battery cells in different cell groups are connected in series, as a result of which electrical and mechanical safety is ensured despite the high packing density.

Battery cells connected in parallel each define a battery group in the cell module. The battery groups present in the cell module are preferably of the same size, i.e. they contain the same number of battery cells. The number of battery cells in a battery group can preferably be divided by the number of holding sections per cell group, as a result of which the advantage of a high packing density is combined with maintaining flexibility with regard to the electrical wiring.

According to a specific exemplary embodiment, the cell module comprises, for example, a total of 297 cell positions, oriented in 11 rows and 27 columns, with three battery cells being combined in rows to form a cell group each. This structure allows a variety of circuit configurations. The battery cells can be connected in parallel in rows and the rows in series. This wiring is referred to as "basic wiring" and abbreviated to "11s27p", where in the s-p nomenclature "s" stands for serial and "p" for parallel. The basic wiring is a preferred configuration with regard to busbar geometry and uniform current distribution. However, the grouping of the battery cells allows further connection patterns or configurations, taking into account the safety aspect that a series connection of battery cells at a small distance is to be avoided.

A cell module preferably comprises a plurality of cylindrical battery cells and two cell holders in order to hold the battery cells on both sides in the direction of the cell axis by one cell holder each.

The above object is also achieved by a method for producing a cell holder, preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell holder being set up to at least one cylindrical battery cell defining a cell axis keep. According to the method, the cell holder is injection molded from a plastic using a mold that preferably has two mold halves. If several tool parts/tool halves are used, they can be moved, pivoted or moved relative to one another in some other way to open the tool. In any case, the cell holder can be removed from the mold after the plastic has hardened sufficiently in the mold.

According to the invention, the cell holder is removed from the mold along a demolding direction, with the demolding direction and the cell axis not running parallel.

Since the demolding direction and the cell axis do not run parallel, the contact between the battery cell and the cell holder can be improved, since the demolding angles that are necessary or usual for injection molding do not result in any loss of quality, but can be used directly to stabilize the battery cell(s).

This technical effect is achieved in particular with a cell holder as described above. The features, technical effects, advantages and exemplary embodiments that have been described in relation to the cell holder apply analogously to the method.

Further advantages and features of the present invention can be seen from the following description of preferred exemplary embodiments. The features described therein can be implemented on their own or in combination with one or more of the features set out above, insofar as the features do not contradict one another. The following description of preferred exemplary embodiments is made with reference to the accompanying drawings.

character list

• 1 einen Ausschnitt eines herkömmlichen Zellhalters, dargestellt in einem Querschnitt parallel zur Zellachse, mit übertrieben dargestellten Entformungswinkeln und einer Entformungsrichtung parallel zu den Zellachsen;
• 2 eine Draufsicht auf einen Zellhalter mit einer Vielzahl von Halteabschnitten, angeordnet in relativ zueinander versetzten Reihen;
• 3 einen Ausschnitt eines Zellhalters, dargestellt in einem Querschnitt parallel zur Zellachse, dessen Entformungsrichtung nicht parallel zur Zellachse verläuft;
• 4 einen perspektivischen Ausschnitt eines Zellhalters, wobei ein freier und ein mit einer Batteriezelle bestückter Halteabschnitt gezeigt sind;
• 5 einen perspektivischen Ausschnitt eines Halteabschnitts eines Zellhalters, betrachtet schräg in den Halteabschnitt hinein;
• 6 eine Ansicht von unten auf einen Halteabschnitt eines Zellhalters mit eingesetzter Batteriezelle;
• 7 einen perspektivischen Ausschnitt eines Zellhalters gemäß einem weiteren Ausführungsbeispiel;
• 8 einen perspektivischen Ausschnitt des Zellhalters, betrachtet aus einer anderen Perspektive;
• 9 eine Draufsicht auf den Zellhalter;
• 10 eine schematische, qualitative Darstellung einer Gruppierung von Batteriezellen mit unterschiedlichen Abständen;
• 11 eine perspektivische, auseinandergezogene Ansicht eines Zellmoduls in einer Grundverschaltung; und
• 12a, 12b und 12c schematische Darstellungen alternativer Verschaltungen.

Preferred further embodiments of the invention are explained in more detail by the following description of the figures. show:

• 1 a section of a conventional cell holder, shown in a cross section parallel to the cell axis, with exaggerated draft angles and a direction of draft parallel to the cell axes;
• 2 a plan view of a cell holder with a plurality of holding sections, arranged in rows offset relative to one another;
• 3 a section of a cell holder, shown in a cross section parallel to the cell axis, whose demoulding direction does not run parallel to the cell axis;
• 4 a perspective section of a cell holder, wherein a free and equipped with a battery cell holding section are shown;
• 5 a perspective section of a holding section of a cell holder, viewed obliquely into the holding section;
• 6 a view from below of a holding portion of a cell holder with a battery cell inserted;
• 7 a perspective detail of a cell holder according to a further embodiment;
• 8th a perspective section of the cell holder, viewed from a different perspective;
• 9 a plan view of the cell holder;
• 10 a schematic, qualitative representation of a grouping of battery cells with different distances;
• 11 a perspective, exploded view of a cell module in a basic configuration; and
• 12a , 12b and 12c schematic representations of alternative connections.

Detailed description of preferred embodiments

Preferred exemplary embodiments are described below with reference to the figures. Elements that are the same, similar or have the same effect are provided with identical reference symbols in the figures, and a repeated description of these elements is sometimes dispensed with in order to avoid redundancy.

the 2 is a plan view of a cell holder 1 with a multiplicity of holding sections 10, which are used to hold cylindrical battery cells 2, cf. 3 , 4 and 6 , are set up. The cell holder 1 is preferably made of a plastic, in particular by injection molding. Furthermore, the cell holder 1 is preferably designed in one piece or essentially in one piece.

The holding sections 10 form concave sections, ie they are cup-shaped or in the form of indentations, so that one of the two axial ends of a battery cell 2 can be inserted into such a holding section 10, as can be seen particularly clearly from FIGS 3 and 4 emerges.

In the present exemplary embodiment, the holding sections 10 are arranged in rows R, with adjacent rows R being offset by the dimension of half a holding section 10, resulting in a honeycomb structure or a structure of the closest circular packing. In this way, the number of battery cells 2 accommodated per unit area can be maximized. However, the holding sections 10 can also be arranged in a different way, for example without offsetting adjacent rows R.

The holding sections 10 comprise a base 11 which, when the battery cell 2 is inserted, is in contact with at least part of the corresponding base area 2a of the battery cell 2 and in this way supports the battery cell 2 axially, ie along the cell axis A (cf. 3 ) fixed. It should be noted that the bases 2a of the battery cells 2 do not have to form perfect planes, but may have curvatures, deformations and the like in the axial direction A of the battery cell 2, as is shown, for example, in FIG 6 is indicated.

The base 11 preferably has a base opening 11a, which can be a generous recess in order to enable or facilitate electrical contacting of the battery cells 2 .

The holding sections 10 also include side walls 12, which are designed to fix the battery cells 2 in the lateral direction, ie perpendicular to the cell axis A, in the plugged-in state. The side walls 12 have a special structure that improves the hold of the battery cells 2 . Such an improvement in the interface between the holding section 10 and the battery cell 2 can be achieved by utilizing the production-related draft angle a, cf. 3 , take place.

With reference to the 3 the direction in which the cell holder 1, if it is manufactured as an injection molded part, is removed from the corresponding mold (not shown in the figures) is designated as the demolding direction E. According to the present exemplary embodiment, the demolding direction E and the cell axis A form an angle β that differs from zero and, in the case of vertical battery cells 2, corresponds to the demolding angle a. In other words, the demolding direction E and the cell axis A are not parallel. Since the demolding direction E and the cell axis A do not run parallel, the contact between the battery cell 2 and the side walls 12 of the corresponding holding section 10 can be improved, as explained in more detail below.

According to the present embodiment, the side walls 12 of a holding portion 10 comprise a contact surface 12a, which is substantially perpendicular to the base 11, can be connected to the base 11 and is concave, in particular cylindrical, perpendicular to it in a way that it is curved with a corresponding section of the lateral surface 2b of the battery cell 2 corresponds, thus with the battery cell 2 is in surface contact. The cylindrical contact surface 12a is preferably curved in a circle perpendicular to the cell axis A in order to interact optimally with circular-cylindrical battery cells 2 .

The terms "cylindrical" and "circular" do not necessarily define a complete cylinder circumference or circle. Rather, the contour of a corresponding section, i.e. segment, is included, since the cylindrical contact surface does not completely surround the battery cell, but only lies flat on a section of the battery cell circumference, for example in the range from 20° to 90°.

The side walls 12 also comprise one or more, preferably exactly two, deformable contact sections 12b for each holding section 10. The deformable contact sections 12b are at least partially deformed when the battery cell 2 is inserted, in contrast to the contact surface 12a, as is particularly clear from FIG 3 emerges. The contact sections 12b are preferably elastic, ie spring-like in design, and for this purpose are preferably not connected or not completely connected to the base 11 . The deformable contact sections 12b can make a planar contact or a line contact in the axial direction with the lateral surface 2b of the battery cell 2 .

In the unequipped state, ie without an inserted battery cell 2, the contact surface 12a and a corresponding contact section 12b preferably form an angle 2a that is different from zero, cf. 3 , where a denotes the draft angle mentioned above. The demolding angle a defines a tapering of the holding section 10 starting from the bottom 11 in the demolding direction E, which on the one hand simplifies the removal of the cell holder 1 from a corresponding injection molding tool and on the other hand causes a reliable clamping of a battery cell 2 to be inserted due to the deformability of the contact sections 12b. At the same time, precise positioning and alignment of the battery cell 2 is ensured by the vertical contact surface 12a.

In the present exemplary embodiment, the side walls 12 for each holding section 10 include a vertical contact surface 12a and two opposite contact sections 12b. There are thus three contact points per battery cell 2, with at least the contact surface 12a realizing a planar contact. The contact sections 12b preferably run obliquely, viewed relative to the cell axis A, so that they act as insertion chamfers for a corresponding battery cell 2 . The contact portions 12b are deformed during cell assembly. They can be produced by injection molding with the usual draft angles and from only two mold halves.

The contact surfaces 12a and deformable contact portions 12b can be structurally integrated with each other, as is particularly clear from the 4 and 5 emerges. The side wall 12 of a holding section 10 that carries the contact surface 12a can simultaneously form a contact section 12b of an adjacent holding section 10 . For example, the contact portion 12b of the support portion 10 of a given row R is at the level of the apex of the contact surface 12a of an adjacent support portion of the row R-1, cf 3 .

the 7 until 9 12 show a further exemplary embodiment which differs from the previous exemplary embodiments in the structure of the contact surface 12a. While the contact surface 12a according to the embodiment of 2 , 4 and 5 is cylindrically curved (seen in a cross-section parallel to the bottom 11) in order to make areal contact with the lateral surface 2b of the battery cell 2, the contact surface 12a and the lateral surface 2b of the battery cell 2 according to the present exemplary embodiment essentially form a line contact at two points, as is particularly evident from the 9 emerges. The contact surface 12a therefore does not have to correspond to the curvature of the battery cell 2, but can, for example, run in a straight line or in the form of a polygon, seen in a cross section perpendicular to the base 11. In this way, the cell holder 1 can be used particularly flexibly for battery cells 2 of different shapes and/or dimensions.

The subdivision of the side walls 12 into a contact surface 12a and one or more deformable contact sections 12b means that the lateral surface 2b of an inserted battery cell 2 can remain free between these contact areas and does not have to be completely surrounded by the material of the cell holder 1 over 360°.

This allows cell groups 1a to be created from battery cells 2 lying directly next to one another. In the 2 cell groups 1a each consisting of three holding sections 10 are shown as an example. The cell groups 1a are separated from one another in the direction of the R rows by stabilizing webs or group walls 1b. Depending on the application, the material of the cell holder 1, the requirement for stability and the like, more or fewer holding sections 10 can be combined to form a cell group 1a. Such a combination in turn results in material and space savings, as a result of which the cell modules 100 (cf. 11 ) can be made particularly compact.

The battery cells 2 of a cell group 1a are preferably electrically connected in parallel, since in this case the lateral surfaces 2b of the battery cells 2 carry the same electrical potential and should also touch.

The cell holder 1 can be produced in a resource- and cost-efficient manner, since the geometries of the holding sections with the corresponding side walls 12 can be injection molded in a simple manner, for example by means of corresponding mold halves. The holding sections 10 enable exact positioning and a defined mechanical connection of the battery cells 2 to the cell holder 1. The cell assembly is facilitated by insertion bevels formed by the deformable contact section 12b. The cell holder 1 allows a constant component wall thickness to be maintained, which has an advantageous effect on manufacturability and the fire protection class to be achieved. The holding sections 10 allow the battery cells 2 to be arranged directly next to one another in a space-saving manner. The effects achieved are also comparatively insensitive to manufacturing tolerances of the cell holder 1 and the battery cells 2. Due to its insensitivity to fluctuating cell diameters, the cell holder 1 is able to hold battery cells 2 from different manufacturers without modification, which saves resources and costs when changing battery cell types / manufacturers can be saved.

Coming back to with reference to the 2 described grouping of battery cells 2, the grouping can be realized by different distances between adjacent battery cells 2 within a cell group 1a and adjacent battery cells 2 adjacent cell groups 1a. This is in the 10 shown schematically, where a1 is the cell spacing within the group, ie the spacing between adjacent battery cells 2 within a cell group 1a, and a2 is the cell spacing in groups, ie the spacing between adjacent battery cells 2 adjacent cell groups 1a. In this case, the shortest distance between the lateral surfaces 2b of the corresponding battery cells 2 is used in each case.

The tripartite grouping according to the 2 and 10 is only an example, and more or fewer battery cells 2 can be combined to form a cell group 1a. If the grouping is realized by different distances a1, a2, the cell holder 1 does not necessarily have to have webs or group walls 1b in the sections with larger distances a2, although this according to FIG 2 is a preferred embodiment.

Units of battery cells 2 with a small distance a1, i.e. battery cells 2 within a cell group 1a, are particularly preferably connected in parallel, while battery cells 2 of different cell groups 1a are connected in series in this case. In this way, a higher packing density compared to equidistant cell placement is achieved without sacrificing security.

the 11 1 shows a cell module 100 with two cell holders 1 and battery cells 2 sandwiched between them. A housing section 3, a cooling section 4 and a wiring section 5 are also shown.

In the embodiment of 11 the cell module 100 includes a total of 297 cell positions, oriented in 11 rows R and 27 columns, with three battery cells 2 being combined in rows to form a cell group 1a each. Furthermore, the battery cells 2 are connected in parallel in rows and the rows R are connected in series. This wiring is referred to as "basic wiring" and abbreviated to "11s27p", where in the sp nomenclature "s" stands for serial and "p" for parallel. The basic wiring is with respect to busbar geometry, through the wiring section 5 of 11 shown, and even current distribution is a preferred configuration.

However, the grouping of the battery cells 2 allows further connection patterns or configurations, taking into account the safety aspect that a series connection of battery cells 2 at a small distance a1 is to be avoided. the 12a until 12c show exemplary configurations that can be sensibly represented in terms of busbar geometry and current distribution. In this case, fields of the same gray level identify battery cells 2 connected in parallel, while fields of different gray levels form units connected in series. The number in brackets after the sp nomenclature designates the number of positions actually occupied by battery cells 2 in the cell module 100, fields marked with "u" ( 12b and 12c ) are unoccupied. The configurations according to 11 , 12a , 12b , 12c are not complete, further variants are also conceivable.

In addition, the number and configuration of sensible connection patterns vary depending on the number of battery cells 2 combined into cell groups 1a. From a purely electrical point of view, in extreme cases, to achieve maximum packing density, a cell module 100 can comprise an entire battery group (= logical cell, group of battery cells 2 connected in parallel). . For mechanical reasons, however, such a battery group is usually subdivided into several cell groups 1a, which also allows flexibility with regard to possible electrical interconnections without having to change the structure or the design of the cell holder 1 for this purpose. Compared to a conventional design, a higher packing density is still achieved with less material used, while maintaining flexibility in terms of electrical wiring and safety.

The behavior section 5 is preferably set up in such a way that potential differences between adjacent battery cells, i.e. serial interconnections, only ever occur along partition walls, in particular group walls 1b.

The use of different distances a1, a2 between battery cells 2, in particular the grouping of the battery cells 2 using group walls 1b, enables the packing density to be optimized in comparison to equidistant cell placement without sacrificing safety. This results in less material being used, lower costs and a lower weight of the cell holder 1. If the number of holding sections 10 per cell group 1a is a divisor of the number of battery cells 2 in a battery group, i.e. group of battery cells 2 connected in parallel, the advantage of a high Packing density combined with maintaining flexibility with regard to the electrical wiring.

As far as applicable, all individual features that are presented in the exemplary embodiments can be combined with one another and/or exchanged without departing from the scope of the invention.

Reference List

1

cell holder

1a

cell group

1b

group wall

2

battery cell

2a

Floor space

2 B

lateral surface

3

housing section

4

cooling section

5

interconnection section

10

holding section

11

floor

11a

bottom opening

12

Side wall

12a

contact surface

12b

Deformable contact section

100

cell module

A

cell axis/axial direction

E

demolding direction

K

contact area

R

Row

a

draft angle

β

angle

a1

Group internal cell spacing

a2

Groupwise cell spacing

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 2010/0136413 A1 [0004]

Claims (15)

Cell holder (1) for holding cylindrical battery cells (2), preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell holder (1) having: a plurality of holding sections (10), each having a base (11) and side walls (12) and thus each forming a section which is set up to form a base surface (2a) and at least sections of a lateral surface (2b) for each battery cell (2) to pick up and fix; whereby the side walls (12) of the respective holding sections (10) comprise: at least one contact surface (12a), which is arranged in a contact area to the battery cell (2) essentially perpendicularly to the base (11) and is set up to to be in planar or linear contact with a section of a lateral surface (2b) of the battery cell (2), and at least one deformable contact section (12b) which is set up to move into the corresponding holding section (10) when the battery cell (2) is inserted to deform. Cell holder (1) according to claim 1 , characterized in that the contact surface (12a) is connected to the base (11) and/or the deformable contact section (12b) is not or not completely connected to the base (11) and/or the contact surface (12a) in a cross section parallel to the bottom (11) runs concavely curved. Cell holder (1) according to claim 1 or 2 , characterized in that the contact surface (12a) has a cylindrical or part-cylindrical shape, wherein the cylindrical contact surface (12a) is preferably circularly curved in a cross-section parallel to the bottom (11). Cell holder (1) according to one of the preceding claims, characterized in that the contact surface (12a) and the deformable contact section (12b) form an angle that is not equal to zero when the battery cell (2) is not inserted. Cell holder (1) according to one of the preceding claims, characterized in that the holding sections (10) each comprise exactly two deformable contact sections (12b). Cell holder (1) according to one of the preceding claims, characterized in that the side wall (12) of a holding section (10) carrying the contact surface (12a) has a deformable contact section (12b) of an adjacent holding section (10). Cell holder (1) according to one of the preceding claims, characterized in that one or more of the holding sections (10) are designed such that their side walls (12) do not completely enclose the lateral surface (2b) of a corresponding battery cell (2) used. Cell holder (1) for holding cylindrical battery cells (2), preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell holder (1) having: a plurality of holding sections (10), each having a base (11) and side walls (12) and thus each forming a section which is set up to form a base surface (2a) and at least sections of a lateral surface (2b) for each battery cell (2) to pick up and fix; whereby the holding sections (10) are set up in such a way that battery cells (2) inserted therein have at least partially different distances (a1, a2) to their nearest neighbors. Cell holder (1) according to one of the preceding claims, characterized in that several, preferably three, holding sections (10) are combined to form a cell group (1a) each, with adjacent cell groups (1a) preferably being separated from one another by means of a group wall (1b). Cell holder (1) according to claim 9 , characterized in that the holding sections (10) are set up so that the distance (a1) between adjacent battery cells (2) within a cell group (1a) is smaller than the distance (a2) between adjacent battery cells (2) of adjacent cell groups (1a). Cell holder (1) according to one of the preceding claims, characterized in that the holding sections (10) are arranged in rows (R), the holding sections (10) of adjacent rows (R) being offset, preferably offset by the dimension of half a holding section (10). Cell holder (1) according to claim 9 or 10 and claim 11 , characterized in that the holding sections (10) each cell group (1 a) are in a row (R). Cell module (100), preferably for use in a traction battery for electric or hybrid vehicles or vehicles with fuel cells, the cell module (100) having: at least one cell holder (1) according to one of the preceding claims; a plurality of battery cells (2) each inserted into a holding portion (10) of the cell holder (1) and thereby fixed; and a wiring section (5) which electrically connects the battery cells (2) to one another. cell module (100) after Claim 13 and claim 9 , characterized in that the interconnection section (5) is set up so that battery cells (2) within a cell group (1a) are connected in parallel, while battery cells (2) of different cell groups (1a) are connected in series. cell module (100) after Claim 14 , characterized in that battery cells (2) connected in parallel in the cell module (100) each define a battery group and the number of battery cells (2) in a battery group can be divided by the number of holding sections (10) per cell group (1a).

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